I love this topic! I have been wanting to ask a similar question.

So far, since I am just getting back into the hobby after a long lapse, I mainly use my vintage computers to help me build a working archive of software that I might want to use on a variety of classic mac computers. (Everything from various versions of system software to utilities like Stuffit, Norton, etc.)

Eventually, I'd like to spend more time building up a library of vintage games. And I'd really like to see those toasters fly again. But I am very interested to hear how others are using their classic machines.